Carpet Beetle Life Cycle

Carpet beetle (anthrenus) is among the common pests that also live in your home. They live in any item with animal hair like fabrics, upholstered furniture, and other items. Aside from common fabric items, they can also infest mice and bird nests. When inspecting various infested items, you will find this insect in various stages of their life cycle.

There are many homeowners that are thinking of this as a new pest scare. However, you shouldn’t worry as long as you know how to control an infestation. Carpet beetle larvae are the phase when these insects can ruin items the most. With the right identification of larvae, you can determine the suitable treatment for your current level of infestation.

Carpet Beetle Life Stages

These beetles go through a complete metamorphosis that includes the egg, larval, pupal, and adult stages. Depending on the temperature in the surrounding, carpet beetles may take a minimum of four months to a maximum of one year to complete all stages.

Adults usually mate nearby light sources. After mating, females will start laying eggs that will hatch into larvae, enter the pupal stage, and then enter the adult phase. Below is every stage of life that these insects go through:


Females lay a lot of egg batches with each batching having approximately 20 to 100 eggs. Their eggs are usually white and oval shaped. Each measures about 0.35 mm wide and about 075mm in length.

Though these pests can survive outdoors, there are times when mothers would lay their eggs indoors. They try to as near as possible to their food source.

When mothers are able to lay eggs indoors, it usually takes around five to twenty-one days for these to hatch. The period always depends on the prevalent climatic conditions and also the species of carpet beetles. Eggs are most likely hidden in dark closets and spots near baseboards.


When eggs hatch after about three weeks, they will turn into larvae. Larvae are usually 5mm in length, has oval-shaped bodies, and are covered in brown hair.

Larval food sources range from hair fabrics, dander to animal or plant product materials. They can also eat packaged food like cereals and flour.

To check an infestation, you will most likely see larval skin scattered under furniture or inside dark spaces. Larvae go through moulting. However, the total number of instars always depend on the species. Instars may range from six to twelve.

It will take around two to three months till the larvae turn into pupas. At this life stage, larvae can survive even without consuming any food.


This is the stage where the insects will develop a skin similar to a cocoon. It will take around twenty days prior to entering the adult phase. In this stage, the pupas are white and often spent on or near items that they are eating while they are in the larval stage.


After around three weeks, young carpet beetles will mature and then become adults. Once the beetles reach this stage, each beetle will reach a length of 3.5mm. They may appear solid black or moult with white, brown, or black.

As mentioned, the colours always depend on the species. Unlike larvae, adults don’t pose any form or harm. Though they feed on pollen, adults aren’t leaving flowers damaged.

When you have an infestation, you will oftentimes see adults flying through open doors or windows. Light attracts these insects, so they will most likely head outside where they see the light.

A week after entering adulthood, the cycle will start again as females will start laying eggs. This results in the rapid increase of population. Thus, this is resulting in the quick spread of an infestation.

How Different Species Go Through Their Life Stages

Different species may have certain differences as they go through their life stages. Some of the common species you may find at home and the lifecycle are the following:

Varied Carpet Beetle

This species is also called as anthrenus verbasci and is about 1.10 of an inch in length. They are black in colour and has irregular patterns of dark yellow, white, and brown on its elytra or wing covers. In time, these patterns wear off, so adults will appear solid black or brown.

When outdoors, females usually look for wasp, bee or bird nests, and at times spider webs where they can lay eggs. These areas are chosen by females since these may have dead insects, pollen, beeswax, feathers, and other items that may serve as food.

Indoors, eggs can be laid near or on rugs, wool carpets, and other items that larvae can eat. It is by early summer or spring when adults emerge.

Unlike adults, mature larvae are a bit longer. They are covered with thick hair. When disturbed, they can extend upright and form a round plume.

Usually, they have dark and light brown alternating stripes. You can identify them easily because of their narrower front and broader rear.

Furniture Carpet Beetle

Also called as A. flavipes, these beetles are slightly rounder and larger than anthrenus verbasci species. Their markings and coloration vary, but they have distinguished block spots mixed with the dark yellow to orange and white scales on its elytra. Once these scales wear off, they will appear solid black with white undersides.

The larvae will appear white but then changes to chestnut brown to dark red. Larvae have narrower rear and broader front than anthrenus verbasci but feed on similar items as anthrenus verbasci.

Black Carpet Beetles

Larvae and adults of Attagenus unicolor are different from the description of carpet beetles. Adults of this species have a length ranging from 1/8 to 3/16 of an inch. They are usually dark brown and shiny black in colour and has brownish legs.

Full-sized larvae may have a length of 5/16 inch and colour ranges from light brown to black. The larvae are also hard, shiny, and smooth. They are short but has stiff hairs covering the body.

Their bodies are narrowing toward the rear and have tufts of long hairs in the ends. In California as well as other arid areas, this type of beetle is infesting stored products than fabrics.

Handling an Infestation

There are various ways of handling an infestation. One way is washing and drying items in high heat. For delicate items, you can have them dry cleaned. If the infestation is difficult to control, you can use various pest control methods.

You can try using insecticides and other treatments. However, if you want to save time and effort and has the means to pay for services, you can resort to calling experts.